However, the efficacy of PARP inhibitor treatments in patients with BRCAness (ATM, BAP1, BARD1, BLM, BRIP1, CHEK2, FAM175A, FANCA, FANCC, NBN, PALB2, RAD50, RAD51, RAD51C, and RTEL1), or in HRD PDAC patients, remains unclear [106]. This evidence concerns the gene RTEL1 and hypoparathyroidism-retardation-dysmorphism syndrome.